Semi-manual machine tool for treating flat and horizontal surfaces

ABSTRACT

Disclosed is a semi-manual machine tool for treating flat horizontal surfaces, this machine including: a base; a drive plate connected to the base having a lower face adapted to be connected to a working tool; a motor; a transmission system between the motor and the drive plate; a handle for controlling the machine; and a working tool connected to the lower face of the drive plate. The drive plate is connected to the base in a manner sliding along a direction parallel to the direction of translation of the machine tool, i.e., parallel to the longitudinal axis of the machine tool, the transmission system being configured to impart to the drive plate a reciprocating rectilinear movement along the longitudinal direction.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is the U.S. national phase of International ApplicationNo. PCT/IB2020/057348 filed Aug. 4, 2020 which designated the U.S. andclaims priority to IT Patent Application No. 102019000014037 filed Aug.5, 2019, the entire contents of each of which are hereby incorporated byreference.

BACKGROUND OF THE INVENTION Field of the Invention

The present invention concerns a motorized semi-manual machine tool fortreating flat horizontal surfaces. In particular, the invention relatesto a machine tool that moves according to a frontal linear motion.

The field of application of this machine tool is that, if equipped withspecific tools, of carrying out a treatment or process such as grinding,polishing, brushing or antiquing of said surfaces.

Description of the Related Art

The machine to which the present invention refers concerns the treatmentof flat horizontal surfaces typically floors, or pedestrian or walkablesurfaces, for example of homes, boars, jetties and walkways, etc.

More in particular, said machine tool is particularly suitable if saidsurfaces have grout lines or veins, such as those found on certainwooden, stone, ceramic or similar floors, more specifically, forexample, parquet, marble or covered with square tiles made of variousmaterials, such as ceramic or the like.

Generally, in prior art semi-manual motorized machine tools used forthese types of treatments and processes, for example grinding machinesfor floors or other flat horizontal surfaces, the tools move accordingto a rotary, orbital or planetary rotary motion. Therefore, thesemachines perform a processing action of circular type, or with acircular component, on the surface being treated.

On surfaces with grooves, such as the grout lines present between tilesor between adjacent wooden boards, this type of circular/orbitalmovement mainly concerns the raised parts of these surfaces.

In profiles that are not perfectly flat and continuous, it is thereforedifficult to reach said grooves with the tool, whether this is a brush,a paper, cloth or mesh abrasive disc, or a nonwoven pad.

Consequently, this means that with these prior art machines a great dealof time is required to treat the grout lines requires, as numerous stepsare necessary in order to treat the whole of the surface involved.

However, in this way there is the risk of removing too much material onsaid raised parts, changing their appearance, or in some cases, damagingthem.

Moreover, treating said grooves with these machines does not providesatisfactory results, as it is not easy to pass over all the smallportions that were left untreated in the previous passes.

Another limit of prior art machines is that the circular movement, orwith a circular component, of the tools leaves circular or curvedprocessing marks on the surface. In the case of surfaces that have groutlines or veins of the material aligned along a main direction, thesecircular processing marks have a rather unattractive appearance.

SUMMARY OF THE INVENTION

The machine tool according to the present invention solves the aforesaidproblems as, due to the linear movement imparted to the working tool bythe machine, said grooves and said surfaces can be treated along adirection substantially aligned with said grooves or veins. A firstadvantage is that of obtaining an improved treatment, while a secondadvantage is that of reducing the times required to process a givensurface.

Moreover, this machine tool does not leave circular marks on the surfacebeing processed, representing a further advantage, as these signs arenot aesthetically pleasing.

These and other objects are achieved by a motorized semi-manual machinetool, comprising at least:

-   -   a base;    -   a drive plate having a lower face to which a working tool can be        attached;    -   a motor;    -   a transmission system between said drive plate and said motor;        and    -   a handle for controlling the machine.

The drive plate is connected to the base in a manner sliding along adirection parallel to the direction of translation of the machine tool,i.e., parallel to the longitudinal axis of the machine.

Said transmission system is configured to impart to said drive plate,and hence to the tool, a reciprocating rectilinear movement along saidlongitudinal direction.

In detail, the two elements, base and drive plate, are typicallymutually superimposed, with the drive plate that, in a position of useof the machine, has the lower face facing the surface to be treated.Said lower face is typically substantially flat.

Hereinafter, the terms “front”, “rear” “below”, “above”, “upper”,“lower” and “side” are defined for a machine tool in a normal positionof use.

According to an advantageous aspect of the present invention, thecontact area between the tool and the surface to be treated extendstransversely, i.e. extends to a greater degree along a directionparallel to the transverse axis of the machine.

In practice, said contact area has an extension in width (L) greaterthan its longitudinal extension (P), i.e. depth.

According to a preferred variant, said contact area has a ratio (L)/(P)ranging from 1 to 6, preferably from 3.5 to 4.5. Typically, the contactarea has a substantially rectangular planform.

According to a preferred variant, the contact area can coincide with thearea of the lower face of the drive plate. In practice, according tothis variant the one or more tools that can be connected to the driveplate have a working area extending to a greater degree in transversedirection. The lower face of the drive plate thus offers a supportsurface for the connection of a tool or of several tools together havingsubstantially the same dimensions and proportions.

The base can have various forms as a function of the position of themotor or of aesthetic choices, for example substantially parallelepipedor cylindrical. Typically, the base also has a substantially rectangularplanform extending to a greater degree along a transverse direction.

The base has a lower (or inner) side on which the drive plate ismounted, which, during operation of the machine tool, is movablelongitudinally, i.e., as indicated previously, according to areciprocating rectilinear movement along a direction parallel to thedirection of translation of the machine tool.

In particular, the drive plate has a movement preferably ranging from 5to 30 mm.

According to an aspect of the invention, the machine comprises linearguide means to guide the reciprocating rectilinear movement of the driveplate.

According to a preferred variant, said linear guide means comprise atleast one linear guide whose track is preferably fixed to the base whilethe slide is integral with the drive plate. Preferably at least twolinear guides are provided, arranged symmetrically with respect to thecentreline of the drive plate.

According to an aspect of the invention, the motor is mounted on amount, connected to the base, which extends toward the rear part of themachine. In practice, the motor is mounted in a position farther backwith respect to the base.

The motor is positioned so that its rotation axis is substantiallyvertical and the motor shaft is facing downward.

According to this configuration, the transmission comprises a belt thattransmits the rotary motion from a first pulley, mounted on the motorshaft, to a second pulley mounted on a second shaft pivoted in the baseor in the motor mount. The rotary motion of the second pulley isconverted into reciprocating rectilinear motion preferably by means of aconnecting rod-crank mechanism. Alternatively, a Scotch yoke mechanismor other equivalent systems can be used.

The frequency of the reciprocating motion of the drive plate depends onthe geometrical features of the transmission, i.e., of the belttransmission and of the motion conversion mechanism. From testsconducted by the applicant, an optimal range is from 400 cycles/min to1500 cycles/min, more preferably from 500 cycles/min to 1000 cycles/min.

According to a particular embodiment, this machine is equipped withrolling means configured to move said machine tool along a rectilineardirection. The rolling means are preferably wheels, typically two innumber, or ball wheels.

As a function of their positioning, said rolling means can performvarious functions. For example, these means can act purely as an aid formoving the machine tool in an idle condition, for example to transportit to the place of use. According to this variant, in the condition ofuse, the weight of the machine is discharged completely to the driveplate, or to the tool connected thereto.

According to a preferred variant, these means can also help to move themachine during use, preferably along the aforesaid rectilineardirection. In this second variant the rolling means are in contact withthe surface to be treated during operation of the machine; therefore, atleast a portion of the weight of the machine is discharged to them.

Typically, the wheels are positioned behind the motor mount where theydo not obstruct operation of the tool and allow the machine to operateclose to, or flush with, vertical edges or walls.

According to a preferred variant, the motor is positioned with itsrotation axis at a distance (dr) from the axis of the wheels equal orsimilar to the distance (dp) between said wheels and the centreline ofthe drive plate taken in longitudinal direction.

Typically, the ratio (dr)/(dp) between these distances ranges from 0.5to 2, more preferably from 0.65 to 1.5, even more preferably from 0.8 to1.2.

According to an aspect of the invention, the handle for controlling themachine comprises a steering rod that is connected to the motor mountpreferably at the axis of said motor. This steering rod is then fixed ator close to the centre of mass of the machine tool. In general, theconnection point is located at a distance from the axis of the motor,taken along the horizontal direction, of no more than 150 mm, preferablyno more than 100 mm, toward the front or rear part of the machine.

This positioning ensures excellent maneuverability of the machine; inparticular, acting with a minimum variation of the vertical pressure onthe handle, it is possible to charge or discharge the drive plate andhence adjust the pressure that the tool exerts on the surface to betreated.

Preferably, the steering rod is rotatably connected to the motor mount,so as to be able to adjust the angle with respect to the machine withthe ground, and is provided with a blocking device to block said rod ina given position during operation.

BRIEF DESCRIPTION OF THE DRAWINGS

Further features and advantages of the present invention will be moreapparent from the description of a preferred but not exclusive exampleof embodiment of a machine tool as illustrated in the accompanyingfigures wherein:

FIG. 1 is an axonometric view of the machine tool according to anembodiment of the present invention;

FIG. 2 is a side view of the machine tool of FIG. 1;

FIG. 3 is a view of the machine of FIG. 1, sectioned along a verticaland longitudinal plane;

FIG. 4 is a bottom plan view of the machine tool of FIG. 1, without thedrive plate.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

With reference to the accompanying figures, the reference number 1indicates as a whole a machine tool having a base 2, a motor mount 3, ahandle 4, a drive plate 5 and a motor 6.

In the example illustrated, the base 2 comprises a substantiallyparallelepiped shaped box element open at the bottom to accommodate thedrive plate 5.

More in detail, the drive plate 5 is mounted movably on the lower orinner side of the base 2. The drive plate 5 is guided by a pair oflinear guides 7, each comprising a track 7 a, fixed to the base 2, and aslide 7 b integral with a cross bar 8 to which the drive plate 5 isconnected. Said tracks 7 a are oriented along the longitudinal directionof the machine.

Preferably, said cross bar 8 is provided with removable connectionmeans, for example snap fastening means or the like, to allow a rapidattachment and removal of the drive plate 5. The motor mount 3 extendsat the back from the base 2 and, in the variant illustrated, alsocomprises a box element 3 a, with two vertical wings 3 b arranged at therespective sides of the box element 3 a.

The motor 6 is mounted on the motor mount 3 in vertical position withits shaft 6 a facing downward. In detail, the motor 6 is resting againstthe upper side of the box element 3 a which has a seat, not indicated inthe figure, to allow the passage of said motor shaft 6 a.

FIG. 3 illustrates the transmission system, indicated as a whole with10, which transmits the motion from the motor 6 to the drive plate 5.Said transmission system comprises a first pulley 11 fitted onto themotor shaft 6 a, a second pulley 12, mounted on a shaft 13 pivoted onthe motor mount, and a belt 14 wrapped around said first and secondpulleys.

The transmission system further comprises a mechanism for converting therotary motion of the second pulley 12 into the reciprocating rectilinearmotion of the drive plate 5.

Said mechanism comprises a crank journal 15 fixed on the second pulley12, a connecting rod journal 16 fixed on the cross bar 8, and aconnecting rod 17 engaged with said crank and connecting rod journals,respectively with its head and foot.

The action of the connecting rod 17 on the cross bar 8 thus causes areciprocating to-and-from linear movement of the drive plate 5 withrespect to the base 2.

The machine is equipped with two wheels 20 configured to move saidmachine tool 1 along a rectilinear longitudinal direction. The twowheels 20 are connected in the rear part of the motor mount 3, i.e. onthe opposite side with respect to the front side of the base 2.

In a preferred variant, said wheels 20 are mounted sliding verticallywith respect to the motor mount 3 so as to be able to adjust theirposition in height. In the example illustrated, the wheels 20 aremounted on a same support 21 provided with two guide elements 21 a,sliding in seats obtained in the box element 3 a of the motor mount 3and provided with blocking means to block their position with respect tosaid box element.

Adjustment of the wheels 20 makes it possible to use tools withdifferent heights (or thicknesses) to be attached to the drive plate 5,while at the same time allowing said tools always to operate in acondition substantially parallel to the surface to be treated.

The handle 4 is connected to the motor mount 3 by means of a steeringrod 10. As in prior art machine tools with rotary orbital movement, thisrod 18 can be tilted as required, and its position can vary more or lessfrom vertical to horizontal with respect to the surface to be treated.Usually, this position is vertical when the machine tool is idle.

According to the invention, said steering rod 18 is hinged to the motormount 3 so that the rotation axis Xa of the rod 18 is substantiallyaligned, according to a longitudinal direction, with the rotation axisZm of the motor 6. In the variant illustrated, the steering rod 18 hasthe lower end, i.e., facing the machine, that separates into twodiverging branches 18 a respectively hinged to one wing 3 a of the motormount 3.

According to an embodiment, a water dispenser 9 is arranged close to thefront side of the base 2. Typically, the dispenser 9 is in the form ofan elongated tube provided with orifices or nozzles for spraying wateror another suitable liquid. During processing, it is this dispenser 9can be activated so that it sprays water onto the floor surface in frontof the drive plate 5. Said dispenser can be connected to an externalwater source, or the machine can be equipped with a tank for said wateror other liquid and with pumping means.

Preferably, the drive plate 5 has a width ranging from 350 to 550 mm anddepth ranging from 90 to 300 mm, although other dimensions are naturallypossible.

According to the example of embodiment shown in the figures, the driveplate 5 has dimensions of 450 mm in width and 115 mm in depth. Theworking tool 5 has more or less the same dimensions as the drive plate5. The total range of travel C of the drive plate 5 is around 20 mm,i.e., around 17% of its depth.

The drive plate 5 has a lower face adapted to receive and house aworking tool 30, interchangeable as a function of the processingoperation to be carried out and of the type of surface to be treated.This working tool 30 can, for example, be a felt polishing disc, a brushdisc, an abrasive cloth disc, an abrasive mesh disc, a nonwoven disc orthe like.

The invention has been described purely for non-limiting illustrativepurposes, according to some preferred embodiments. The person skilled inthe art can find numerous other embodiments and variants, all fallingwithin the scope of protection of the claims below.

1. A semi-manual machine tool for treating flat horizontal surfaces,said machine comprising: a base; a drive plate connected to the basehaving a lower face adapted to be connected to a working tool; a motor;a transmission system between said motor and said drive plate; a handlefor controlling the machine; and a working tool connected to the lowerface of the drive plate; wherein the drive plate is connected to thebase in a manner sliding along a direction parallel to the direction oftranslation of the machine tool, i.e., parallel to the longitudinal axisof the machine tool, said transmission system being configured to impartto said drive plate a reciprocating rectilinear movement along saidlongitudinal direction.
 2. The machine tool according to claim 1,wherein the contact area between the working tool and the surface to betreated has an extension in width greater than the extension in depth ofthe surface to be treated.
 3. The machine tool according to claim 2,wherein a ratio of the extension in width to the extension in depth isin a range of 1 to
 6. 4. The machine tool according to claim 2, whereinthe tool has the same form and dimension as the drive plate.
 5. Themachine tool according claim 1, wherein the drive plate performs amovement with a range of travel from 5 to 30 mm.
 6. The machine toolaccording to claim 1, comprising at least one linear guide means forguiding the reciprocating rectilinear movement of the drive plate, saidlinear guide means comprising at least one linear guide with a trackfixed to the lower side of the base and a slide, sliding on the track,integral with the drive plate.
 7. The machine tool according to claim 1,wherein the transmission system comprises a belt that transmits therotary motion from a first pulley, mounted on the motor shaft, to asecond pulley mounted on a second shaft pivoted in the base or in themotor mount, said transmission system further comprising acrank-connecting rod mechanism, connected to the drive plate, to convertthe rotary motion of the second pulley into a reciprocating rectilinearmotion of said drive plate.
 8. The machine tool according to claim 1,comprising wheels configured to move said machine tool along arectilinear direction parallel to the longitudinal axis.
 9. The machinetool according to claim 8, comprising a motor mount, integral with thebase, said motor being arranged on the motor mount so that the ratiodr/dp ranges from 0.5 to 2, where dr is the distance of the rotationaxis of the motor from the axis of the wheels and dp is the distancefrom the centreline of the drive plate, taken in longitudinal direction,from the axis of said wheels.
 10. The machine tool according to claim 1,wherein the handle for controlling the machine comprises a steering rodwhich is connected to the motor mount so that the distance between theconnection point of said rod and the axis of the motor, taken along thelongitudinal direction, is no greater than 150 mm toward the front orrear part of the machine.
 11. The machine tool according to claim 1,comprising a water dispenser arranged close to the front side of thebase.
 12. The machine tool according to claim 1, wherein said workingtool is chosen from a felt polishing disc, a brush disc, an abrasivecloth disc, an abrasive mesh disc or a nonwoven disc.
 13. The machinetool according to claim 3, wherein the tool has the same form anddimension as the drive plate.
 14. The machine tool according to claim 2,wherein the drive plate performs a movement with a range of travel from5 to 30 mm.
 15. The machine tool according to claim 3, wherein the driveplate performs a movement with a range of travel from 5 to 30 mm. 16.The machine tool according to claim 4, wherein the drive plate performsa movement with a range of travel from 5 to 30 mm.
 17. The machine toolaccording to claim 2, comprising at least one linear guide means forguiding the reciprocating rectilinear movement of the drive plate, saidlinear guide means comprising at least one linear guide with a trackfixed to the lower side of the base and a slide, sliding on the track,integral with the drive plate.
 18. The machine tool according to claim3, comprising at least one linear guide means for guiding thereciprocating rectilinear movement of the drive plate, said linear guidemeans comprising at least one linear guide with a track fixed to thelower side of the base and a slide, sliding on the track, integral withthe drive plate.
 19. The machine tool according to claim 4, comprisingat least one linear guide means for guiding the reciprocatingrectilinear movement of the drive plate, said linear guide meanscomprising at least one linear guide with a track fixed to the lowerside of the base and a slide, sliding on the track, integral with thedrive plate.
 20. The machine tool according to claim 5, comprising atleast one linear guide means for guiding the reciprocating rectilinearmovement of the drive plate, said linear guide means comprising at leastone linear guide with a track fixed to the lower side of the base and aslide, sliding on the track, integral with the drive plate.